The Regional Transportation District (RTD) of Denver has awarded a $140 million two-phased contract to Balfour Beatty Infrastructure Inc. (BBII) to design and build the southeast light-rail extension.

Design work on the project is expected to begin in spring 2016. Pending the award of a full funding grant agreement from the Federal Transit Administration, construction is expected to be completed by early 2019, RTD officials said in a press release.

The Southeast Rail Extension project will involve the construction of an additional 2.3 miles of light rail on RTD's existing Southeast Rail Line south of Lincoln Avenue in Douglas County, Colo.

The extension will run along Interstate 25, and the project will add two stations.

"This extension will make it possible for RTD to connect people in a rapidly growing part of the metro area to the rest of the region, including Denver International Airport," said Dave Genova, RTD's interim general manager.

The project is expected to cost $233.1 million, including $34 million for environmental analysis, preliminary engineering and design and the acquisition of eight light-rail vehicles.

The remaining $198.7 million will be paid for with federal, private and local funds. Half of the project will be funded by the FTA's New Starts program, RTD officials said.